President Barack Obama's admission that he has no strategy for dealing with the Islamic State (ISIS) is not only startling, but dangerous considering the organization's more than three-year reign of terror in Syria and Iraq, Sens. John McCain and Lindsey Graham write in an opinion piece for The New York Times.

"The president clearly wants to move deliberately and consult with allies and Congress as he considers what to do about ISIS," said McCain, of Arizona, and Graham, of South Carolina. "No one disputes that goal. But the threat ISIS poses only grows over time. It cannot be contained. It must be confronted."

If Obama does adopt a strategy for defeating ISIS, he deserves support, the senators said, but doing so will require a greater sense of urgency and presidential leadership.

It would also require Obama to explain to Americans who are weary of war why ISIS can't be ignored.

"It occupies a growing safe haven the size of Indiana spanning two countries in the heart of the Middle East, and its ranks are filled with thousands of radicals holding Western passports, including some Americans, the senators wrote. "They require nothing more than a plane ticket to travel to United States cities."

They pointed out that Homeland Security Secretary Jeh Johnson has referred to the rise of ISIS as a threat to the United States, warnings that have been echoed by Attorney General Eric Holder, National Intelligence Director James Clapper, Defense Secretary Chuck Hagel, and other key administration officials.

"Americans need to know that ISIS is not just a problem for Iraq and Syria," McCain and Graham said. "It is a threat to the United States. Doing too little to combat ISIS has been a problem. Doing less is certainly not the answer now."

But a strategy against ISIS can't include just a military attack, but must be a comprehensive solution that includes squeezing the organization's finances, a Baghdad government that shares power with the nation's Sunnis, and ending the conflict in Syria, said the senators. Further, there must be a political transition in Syria, as President Bashar al-Assad will "never be a reliable partner against ISIS."

The Assad regime, instead, "has abetted the rise of ISIS, just as it facilitated the terrorism of ISIS’ predecessor, Al Qaeda in Iraq," they said.

Overall, though, ISIS is a military organization and must be "confronted militarily."

And while Obama has begun airstrikes, they are "tactical and reactive half-measures."

Iraq must be confronted also in Syria, said the senators, as "we need a military plan to defeat ISIS, wherever it is."

But while the United States should provide the partners who are already resisting ISIS with weapons, this doesn't mean supporting Iran, they said, as that country "exacerbates sectarian tensions that empower ISIS."

In addition, McCain and Graham said the United States should embed additional special forces and advisers to help its partners fight ISIS, as regional allies should play a role.

"No one is advocating unilateral invasion, occupation or nation-building," they said. "This should be more like Afghanistan in 2001, where limited numbers of advisers helped local forces, with airstrikes and military aid, to rout an extremist army."

A comprehensive strategy, though, requires more troops, assets and time and should include Congress, the senators said.

"We have consistently advocated revising the Authorization for Use of Military Force that has provided congressional backing for counterterrorism operations since September 2001," they said. "Now could be the right time to update this authorization in light of evolving terrorist threats like ISIS. If Mr. Obama provides a coherent strategy and determined leadership, he could win Congress’s support."

History is often kind to presidents who have the courage to change, McCain and Graham said.

"Jimmy Carter changed his policy on the Soviet Union after it invaded Afghanistan," they said. "Bill Clinton changed his policy in the Balkans and stopped ethnic cleansing. And George W. Bush changed course in Iraq and saved America from defeat."

Obama, likewise should accept change and adopt a strategy on ISIS to keep it from growing into a larger danger to the United States and to its allies.

President Barack Obama's admission that he has no strategy for dealing with the Islamic State (ISIS) is not only startling, but dangerous considering the organization's more than three-year reign of terror in Syria and Iraq, Sens. John McCain and Lindsey Graham write in an...